Is there a "significant" difference in sound quality between a bottom of the line mic preamp(ART tube opl-$100) vs. something like a $300-500 range preamp? I'm looking to get good vocal and acoustic guitar recordings through a shure ksm 32/sl. I have the money to spend for the $300-500 preamp. Should I do it? Will I be disappointed with the recordings through the ART tube opl? Does any brand/model stand out among the competition?